Electronic component manufacturers often work together to develop multi-source agreements (MSA) that describe guidelines for manufacturing various electronics modules. For example, there exists an MSA for dense wavelength division multiplexing (DWDM) pluggable transceiver modules and for XFP (10 gigabit small form factor pluggable module) devices. With reference to FIGS. 1A and 1B, a pluggable transceiver module 10 constructed for DWDM communications includes a top module body 14, a bottom module body 18, a transmit port 22, a receive port 26, and a plurality of heat transfer fins 30. Electronic components, which are enclosed by the top module body 14 and bottom module body 18, can include optical transmitters, optical receivers, and various other electronic circuits which provide the functionality of the pluggable transceiver module 10. The transmit port 22 and the receive port 26 facilitate optical communication between the module 10 and other modules and components of a communications system. The ports 22, 26 are coupled through optical communication paths to the enclosed electronic components. During operation, the electronic components generate heat, which is removed through top module body 14 to permit normal operation of the transceiver module 10. The heat transfer fins 30 extending from the top module body 14 help to dissipate the heat generated by the electronic components. In other transceiver modules, the heat transfer fins 30 are not present. Instead, the top module body 14 is relatively flat in the region where the heat transfer fins 30 are typically located.
In some communications applications, multiple pluggable modules 10 are grouped together in an enclosure. The enclosure typically includes printed circuit boards (PCBs), circuitry, and various devices, which are part of an optical communications system. The top surface of the enclosure often is a heat sink. As the modules 10 are inserted into the enclosure, the heat transfer fins 30 of the pluggable modules 10 make contact with the underside of the heat sink to establish a thermal path to help dissipate the heat generated by the enclosed electronic components. Friction between the heat transfer fins 30 and the underside of the heat sink during insertion is undesirable because it increases the force necessary to insert and remove the pluggable modules 10.
Alternatively, a gap can be maintained between the underside of the heat sink and the heat transfer fins 30. The gap eliminates the friction between the heat transfer fins 30 and the underside of the heat sink module; however, the gap also creates a break in the thermal path between the module 10 the heat sink, resulting in increased component temperature and possibly degraded operation of the module 10.
What is needed is a thermal assembly that reduces friction during insertion and provides a thermal path between the module and the heat sink.